By various experiments and analyses, it has been found that the side rigidity of a door is less than that of other parts in an automobile. If the door is side impacted, it goes over a side sill and is pushed toward the passenger compartment, to cause an increase in pelvis injury to a human body.
To solve this problem, a side impact bar assembly is used. Referring to FIG. 1, there is illustrated a front view of a conventional side impact bar assembly mounted to a door inner panel; and FIG. 2 shows a transverse-sectional view taken along the line II-II' of FIG. 1. A side impact bar assembly 50 is provided between the door inner panel 56 and a door outer panel 58, and includes a side impact bar 52. One end of a pair of mounting brackets 54 is fastened to both ends of the side impact bar 52, respectively, and the other end of the pair of mounting brackets 54 is fastened to the door inner panel 56. The side impact bar 52 functions to reinforce side rigidity of a door. Reference numeral 60 represents a center pillar outer panel.
However, in the side impact bar assembly 50 constructed as mentioned above, even though the side impact bar 52 is used to reinforce side rigidity of the door, because a separate mechanism for holding the door to a portion of the pillar panel is not provided when side impact occurs, the door slantingly goes over the center pillar panel 60 and is still pushed into the passenger compartment, as shown by double dotted lines in FIG. 2, whereby the pelvis injury of a human body cannot be remarkedly decreased.
Another side impact bar assembly for settling this problem is disclosed in the Japanese Utility Model Publication No. 90-7613. Referring to FIG. 3, a side impact bar assembly 100 is provided between a door inner panel 104 and a door outer panel 106, and includes a side impact bar 102. In a direction along which the side impact bar 102 extends, a pair of holes 122 are oppositely formed in the door inner panel 104, and both ends of the side impact bar 102 are projected outward through the pair of holes 122, respectively. A guide bracket 108 is secured to the door inner panel 104, and the side impact bar 102 can be moved axially while being supported by the guide bracket 108. A fixed bracket 110 is secured to the outer surface of the side impact bar 102. One end of a spring 112 is fastened to the fixed bracket 110, and the other end of the spring 112 is fastened to the door inner panel 104. The spring 112 functions to pull the side impact bar 102 such that it projects toward a front pillar. In the outside of the door, a center pillar outer panel 114 is formed with a depression 116, and a front pillar outer panel 124 is formed with a rounded portion 118. In the outward end of the rounded portion 118, a projection 120 is defined in the front pillar outer panel 124.
When the door is closed, one end of the side impact bar 102 is contacted with the projection 120, and the other end of the side impact bar 102 is seated on the depression 116. If the door is opened, the other end of the side impact bar 102 is pulled inwardly of the door, and the one end of the side impact bar 102 is moved along the rounded portion 118 to further project outwardly. In a manner described above, the side impact bar 102 continuously moves while the door is closed and opened, to dissipate impact force applied to the door upon side impact toward the center pillar outer panel 114.
However, in the side impact bar assembly 100 having the construction mentioned above, since the side impact bar 102 continuously moves as the door is closed or opened, friction occurs between the rounded portion 118 and the one end of the side impact bar 102 and noise is generated, by which the lifetime of an automobile is shortened and reliable operation of the side impact bar 102 cannot be ensured.